P1280: COMPARING TRANSPLANT OUTCOMES OF AML PATIENTS FOR 2017 AND 2022 ELN RISK STRATIFICATION: A REAL-WORLD STUDY FROM A SINGLE CENTER IN CHINA
Authors: Haixiao Zhang, Erlie Jiang
Journal: HemaSphere (2023)

Topic: 22. Stem cell transplantation - Clinical Background: Leukemia risk stratification guides treatment. Recently, ELN 2022 risk stratification was released, with some changes from the previous ELN 2017. There are few reports of stratification based on ELN 2022, and the applicability of the new stratification needs to be confirmed by large queues. At present, allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is the only way to cure acute myeloid leukemia (AML). It remains to be seen whether ELN2022 can indicate transplant prognosis. Aims: Re-classify from the ELN 2017 to ELN 2022: distribution and outcomes of SCT Compare the prognostic value of ELN 2017 and 2022 risk classifications in transplantation Methods: We enrolled 765 adult AML patients from January 2014 to December 2021 at Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College and patients were diagnosed according to the 2017 WHO definition. 600 patients were included in our study excluding patients with APL, autologous transplantation, incomplete cytogenetic data at initial diagnosis, and lost follow-up (Figure 1). NGS panel targeted 137 genes encompassing mutations referred to ELN 2022 and 2017. High-throughput gene sequencing was performed by ultra-high multiplex PCR exon enrichment, with an average sequencing depth of 800×, Ion Mutation analysis was performed using dbSNP, 1000 Genomes, Polyphen-2, and COSM. Polyphen-2 and COSMIC databases for mutation annotation and amino acid mutation analysis. The detection rate was 97%-98%. FLI3-ITD was simultaneously detected by PCR; NPM1-Exon12, CEBPA- TAD, NPM1-Exon12, CEBPA- TAD, CEBPABZIP, CALR-EXON9, and MPL-Exon10 were detected by Sanger sequencing. Results: •Re-stratification from the ELN 2017 to ELN 2022 classifications Compared with the 2017 ELN risk category, there are 4.36% of patients had a reduced risk category, 8.37% had an increased risk category and 80.38% had an equal risk stratification by the 2022 ELN risk category (Figure 2). •Clinical characteristics of AML patients according to the 2022 ELN classification Characteristics of 600 patients were seen in Table 1. The 5-year OS of favorable, intermediate, adverse groups according to 2022 ELN was 65.8% (95% CI 57.9%~74.7%), 56(95% CI 47.2%~66.5%), and 49.0% (95% CI 40.6%~59.1%) respectively (P=0.039). However, according to ELN 2017, the 5-year OS of favoralbe, intermediate, adverse groups was 64.3% (95% CI 55.8%~74.2%), 61% (95% CI 53%~70.4%), and 49.1% (95% CI 39.4%~61.3%) (P=0.035). •To evaluate the value of ELN 2022 and ELN 2017 for allo-HSCT prognosis, we performed a multiple cox model to calculate the AUC value which showed 66.8% and 68.1% respectively. Summary/Conclusion: Our study showed a single-center outcome of allo-HSCT for adult AML patients from China. ELN 2022 did not show greater survival differences between the unfavorable and intermediate group than ELN 2017. ELN2022 and ELN2017 may both not be appropriate risk systems for predicting allo-HSCT outcomes.Figure 2 Shift of re-stratification from the ELN 2017 to ELN 2022 classifications.a b Figure 3 OS and DFS according to 2022 ELN risk classification Figure 4. ELN 2022 predicts OS of AML patients with allo-HSCT (a); ELN 2017 predicts OS of AML patients with allo-HSCT (a)Keywords: Acute myeloid leukemia, ELN, Allogeneic stem cell transplant